Answer:
I'm not really more than holes tied to more holes. I'm strong as good steel, though not as stiff as a pole.
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
Who is it that rows quickly with four oars, but never comes out from under his own roof?
What is eaten but not grown and was born in water but will disappear if soaked?
It holds most knowledge that has ever been said. But is not the brain, is not the head. To feathers and their masters, it's both bane and boonΒ One empty, and one full.
You use it between your head and your toes, the more it works the thinner it grows.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?